An image processing apparatus, such as a multi-function machine including a printer, scanner, facsimile machine, and copier or functions thereof, generally includes a communicating unit (such as a NIC (Network Interface Card) or a modem (Modulator-Demodulator)) that communicates with an external apparatus (such as a computer or other image processing apparatuses) through a communication medium such as a network or telephone lines. Some of such image processing apparatuses include a function (hereinafter, a sleep function) for shifting into a power-saving state (generally, a sleep mode) with lower power consumption than a normal operation state if a predetermined sleep condition is satisfied in the normal operation state.
The sleep condition includes, for example, a condition that no operation is performed for an operation input unit included in the image processing apparatus and no data are received from an external apparatus through the communicating unit for a certain time period or more. In other cases, the sleep condition may include a condition that the current clock time is within a time zone set in a predetermined time schedule (e.g., weekly schedule).
In the power-saving state, for example, energization (power supply) is cut off to the devices such as a fixing apparatus including a heater and a control circuit, while the communicating unit is often maintained in an energized state. This is because in the power-saving state, energization of devices in non-energized state is automatically resumed according to a request from an external apparatus to allow the devices to automatically return to the normal operation state. For example, in an image forming apparatus shown in Japanese Laid-Open Patent Publication No. 8-101606, when an energized communicating unit receives a print request in a power-saving state, the entire apparatus is energized to form an image in accordance with the received print request.
In an image forming apparatus shown in Japanese Laid-Open Patent Publication No. 2005-186425, when an energized controller receives an access request for a hard disk from an external apparatus through a network in a power-saving state, energization of the hard disk is started to perform the requested processing.
On the other hand, some image processing apparatuses such as a network facsimile apparatus and multi-function machine include a function of transmitting and receiving e-mail. For example, the network facsimile apparatus includes functions for accessing an e-mail server (an example of server apparatuses) through the NIC, for receiving e-mail data addressed to the image processing apparatus (the data to be processed by the image processing apparatus) and for printing the image data included as an attachment file in the e-mail data. Such an image processing apparatus includes a controlling unit that communicates with the e-mail server through the NIC to perform a processing of periodically checking whether or not new e-mail data addressed to the image processing apparatus has arrived (hereinafter, a new e-mail checking processing) and a processing of receiving new e-mail data addressed to the image processing apparatus (hereinafter, called a new e-mail receiving processing). Typically, this controlling unit comprehensively controls the entire image processing apparatus and is often connected to a mass storage apparatus (such as a hard disk drive) for storing various data including e-mail data.
Once the controlling unit stores the e-mail data in a hard disk, etc., a predetermined printing unit prints the image data included as an attachment file in the e-mail data.
However, if the controlling unit performs the new e-mail checking processing periodically or at an arbitrary timing through the communicating unit (NIC) in the image processing apparatus including the receiving function for the e-mail data, the problem of wasting electric power is caused because the controlling unit must always be maintained in the energized state or the start and stop of the controlling unit must be repeated frequently.